The ancients mainly searched for gold with water. This method is very convenient, and it is not easy to find gold. This method is called heavy sand prospecting method, which is a very long-standing prospecting method. It is simple, economical and effective, so it is particularly popular now. He mainly uses the density between gold and other minerals to find gold. For example, in an experiment, gold will generally fall in water, and other minerals or impurities will be easily washed away by water. Generally, mercury will be used for separation. In mercury, gold will generally go down, while other minerals will generally float up, so that gold can be separated. Because the ancients had no special technology, it was especially difficult for them to find gold mines. At first, they found gold on the beach and found the color beautiful. Moreover, it is particularly easy to process, so it is said that it was made into high-grade jewelry at the beginning, and it is particularly beautiful and the price is particularly high. It is particularly scarce, so it has become a very valuable thing, which leads many people to go to the river to look for it. But this kind of large sperm is not particularly abundant, and it is not easy to find. Then many people find that tiny gold is actually very much. Then, if there are a lot of them, they actually add up to a big chunk. So they began to look for tiny gold by the river, which is called gold panning. Because it flows at any time, they found that there must be a lot of gold in the upper reaches of the river. So they went all the way up the river. More and more people are slowly searching for gold. Then they found a lot of rock gold higher on the mountain. The process of prayer is also very complicated. The first one is grinding, that is, grinding the ore into powder. The second is elutriation, in which the mineral-free part is removed by elutriation in water. The third tool is sintering and making them into pellets together. The fourth way is reduction smelting, so that it can form lead blocks containing gold and silver, and the fifth way is ash blowing. Gold and silver with higher purity can be obtained by blowing oxygen.